Heat the granulated sugar and water in a small saucepan, stirring occasionally, until the sugar has just dissolved. Bring to the boil and cook, without stirring, for 5 minutes until golden.
Take the pan off the heat, add the boiling water then stand well back, tilting the pan to mix, until the bubbles have subsided. Divide the caramel between 4, 250 ml (8 fl oz) metal pudding moulds, then swirl the caramel over the inside. Put the moulds in a roasting tin.
Whisk the eggs, egg yolks and caster sugar together to mix. Pour the coconut milk and semi-skimmed milk into a saucepan and bring just to the boil, then gradually whisk into the eggs. Strain into the moulds.
Pour hot (not boiling) water into the roasting tin to come halfway up the sides of the moulds. Cover the tops loosely with buttered foil then bake in a preheated oven, 160°C (325°F), Gas Mark 3, for 30 minutes until just set. Remove from the oven and leave the moulds in the water for 10 minutes. Lift them out, allow to cool then chill for 4 hours or longer until required.
When ready to serve, dip the bases of the moulds into boiling water for 10 seconds, loosen, then turn out on to rimmed serving plates. Decorate with raspberries.